DATEDIF (), which means Date + Dif, is a compatibility function left over from Lotus 1-2-3 that Microsoft adopted in Excel version 2000. It's fallen off current Excel menus, but you can still use it.

In this guide, we’ll explore five innovative Excel formulas: CHOOSECOLS, TEXTSPLIT, TEXTJOIN, REGEX, and GROUPBY, along with AI-powered functions and the versatile DATEDIF function.

To calculate the age, the DATEDIF function, set to check year, determines the number of years between the date in the DOB cell and the current date.